<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="x-ua-compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width,initial-scale=1.0">
    <!--    上述3个meta标签 必须 放在最前面，任何内容都 必须 跟随其后-->
    <title>7.4响应式工具</title>
    <link href="lib/bootstrap/css/bootstrap.min.css" rel="stylesheet">
    <style>
        div{
            border: 1px solid black;
        }
        .container{
            padding: 40px;
        }
    </style>
</head>
<body>
<div class="container">
    <div class="row">
        <div class="col-xs-12 col-sm-6 col-md-4 col-lg-3">
            <span class="visible-xs">✔在手机上可见</span>
            <span class="hidden-xs">在手机上隐藏</span>
        </div>
        <div class="col-xs-12 col-sm-6 col-md-4 col-lg-3">
            <span class="visible-sm">✔在平板上可见</span>
            <span class="hidden-sm">在平板上隐藏</span>
        </div>
        <div class="col-xs-12 col-sm-6 col-md-4 col-lg-3">
            <span class="visible-md">✔在桌面显示屏上可见</span>
            <span class="hidden-md">在桌面显示屏上隐藏</span>
        </div>
        <div class="col-xs-12 col-sm-6 col-md-4 col-lg-3">
            <span class="visible-lg">✔在桌面大显示屏上可见</span>
            <span class="hidden-lg">在桌面大显示屏上隐藏</span>
        </div>
    </div>
</div>

</body>
</html>